Jointed winding stem with screwed-on button



J. SIMON Dec. 19, 1967 JOINTED WINDING STEM WITH SCREWED-ON BUTTON Filed April 11, 1967 FIG/i United States Patent ABSTRACT OF THE DISCLOSURE The present invention has for object a jointed winding stem having a screwed-on button intended to be screwed on a time piece case, the stem comprising an outer part integral with the winding button, an inner part coupled removably to the outer part, a spring disposed in such a way as to axially separate the two said parts one from the other, the inner part being rotatably and axially driven by the action of the movements imparted to the outer part by the button, the outer part effecting an axial movement independently of the inner stem against said spring during the screwing of the button on the case, the assembly being characterized by the fact that said spring is disposed inside said outer part and is comprised in a plane passing through the axis of rotation of the winding stem.

Already known are jointed winding stems combined with a button screwed on the pendant of the case. In order to permit the screwing of the winding button, the external part of the stem, integral with the but-ton, must be able to move axially relative to the inner part of the stem, by a length equal to that necessary to this screwing. During passage from the winding position to the setting position and vice versa, the external part of the stem rigid with the crown must eitect a certain distance in space until the head of the inner stem coupled with play in an elongated opening of the outer stem strikes one of the extremities of this opening.

It has been noted that this play which is necessary to the screwing of the button harms the good functioning of the push piece. At the present momement there can be found on the market a device which permits to obviate this drawback by placing between the outer stem rigid with the button and the inner stem coupled with the outer stem, a helical spring which bears on the one hand against the inner extremity of the outer stem and on the other hand against a shoulder of the inner stem thus exerting an axial pressure tending to separate the two pieces and to make the head of the inner stem bear against the inner extremity of the elongated opening of the outer stem. This spring has for its purpose to facilitate the positioning of the setting lever.

The arrangement of the helical spring placed around a segment of the inner stem has certain drawbacks which can cause unwanted consequences for the user. In effect the diameter of such a spring cannot be exact and can vary in function of its tension and the fatigue of the spring. It has been noted that with use the extremities of such a spring can rub against the part of the case or of the watch causing scratching during rotation of the stem. The inner extremity of the spring can even hook during rotation in the direction opposite to its winding, while the outer extremity is stopped by the diametrical slot made in the outer stem, causing its deterioration.

This arrangement comprises also 'a flaw of the constructional feature.

In the case of small calibres, it is not possible to place a helical or spiral spring, the distance between the coupling of the two stems and the setting lever being too small to place a suflicient number of coils.

3,358,438 Patented Dec. 19, 1967 The accompanying drawing represents by way of example one embodiment of the present invention.

FIGURE 1 is a cross-sectional view showing the button screwed on the case.

FIGURE 2 is a cross-sectional view taken along line II-II of FIGURE 1.

FIGURE 3 is a cross-sectional view with the button unscrewed.

FIGURES 4 and 5 show enlarged details.

The winding stem comprises an outer part 1 secured to the button 2 and passing through a tube '3, fitted in bezel 4 and having a tapped sleeve 5 for screwing the button to the threaded part 6. The outer cylindrical part *1 of the stem has a housing formed by two diametric openings 7 and 8, united by a first, diametrical, counter-sunk slot 9. A second diametrical counter-sunk slot 10 gives access to opening 8 by the extremity of part 1 which is directed toward the inside of the case and defines two elastic jaws 20 and 21 permitting the introduction of the head =11 of the inner part 12 of the stern into opening 8. This head is connected to the body of stem 12 by a narrowed pivot shank of rectangular cross-section 18 the thickness of which corresponds substantially to that of counter-sunk slot 10.

A fiat spring 13 is secured in the outer part 1 of the stem which has for this purpose a third, diametrical, counter-sunk slot M at the outer extremity of the housing formed by openings 7, which is directed toward th outside of the case, and 8 as well as two diametrically opposite grooves 15 on its cylindrical surface. Spring 13 is constituted by a stamped piece and is formed with a base 16 provided with two legs 17. The base is lodged in the slot 14- and the two pieces are elastically hooked in the grooves 15 in such a way that the legs exert a certain radial pressure on the stem. The plane of this spring passes through the rotational axis of the stem and owing to this fact passes through slot 9 lying between openings 7 and 8, its free extremity issuing inside opening 8 and bearing against extremity 19 of head '11.

In order to proceed to the assembly of this stem, the movement having the inner stem 12 is placed in the case then there is introduced the outer part -1 having spring 13 in tube 3. The dimension of slot 10 is slightly greater than the width of extremity 19 of head 11, so that the axial pressure exerted on button 2 provokes the separation of jaws 2t) and 21 which close on pivot shank 18 when head 11 is engaged in opening 8. Extremity 19 of head 11 comes into contact at this moment against the free extremity of spring 13, applying elastically the base of the head against the inner extremity of opening 8 as represented on FIG- URE 3.

In order to pass to the setting position, there is then exerted a traction on button 2 and the jaws 20 and 21 bearing against the base of head 11 axially drive the inner stem 12. To come to the rewinding position there is exerted a pressure on button 2 which provokes a tension of spring 13 until this tension is suflicient to overcome the force of the jumper-spring positioning the stud of the setting lever. At this moment the energy accumulated in spring 13 pushes axially the inner part 12 to return into the position shown on FIGURE 3.

When the button is screwed on sleeve 5 of tube 3 in order to ensure the water-tightness of the winding mechanism, the button causes the axial movement of the external part 1 against the urging of spring 13 which bends, the inner part 12 of the stem being positioned by the pull piece and the jumper-spring. Once the button is completely screwed in sleeve 5 as shown on FIGURES 1 and 2, the extremity of head -11 strikes wall of opening 8 on both sides of slot 9, thus preventing it from exerting excess pressure on spring 13. For this purpose, the width of 3 slot 9 is less than that of face 19 of head 11 in such a way that the latter cannot engage in passage 9 connecting openings 7 and 8.

The described arrangement of the spring does not take up any additional axial room which permits its assembly in a watch of any calibre. In effect, opening 7 serves not only for the passage of the spring but it is also provided in order to give a sufiicient elasticity to jaws 20 and 21 during the introduction of head 11 and the construction between openings 7 and 8 connected by slot 9 serves to limit the race of head 11 which permits to prevent an excessive tension of the spring as above described.

The assembly of the spring is facilitated by slot 9 located in the same plane as slot 14 in which is placed its base 1-6. -It suffices to introduce a spring through slot 10, to push it axially towards opening '8 and opening 9, then to exert a slight pressure in order to hook its legs 17 in grooves 1 5. This operation can be to a great extent effected by means of suitable tools.

It is evident that the water-tightness system of the 'but ton can be of any sort and that the mechanism shown is applicable to all jointed winding stems with screwedon buttons.

What is claimed is:

1. A jointed winding stem assembly having a button adapted to be screwed on a timepiece case, said stem comprising an outer part secured to said button, said outer part having first and second spaced diametrical openings, said openings being connected by a diametri-cal slot to form a housing; said first opening being directed towards the inside of said case and terminating in a pair of elastic jaws delimiting a second diametri-cal slot, said second opening being directed toward the outside of said case and terminating in a third diametrical slot; said stem including also an inner part rotatably and axially driven by movements imparted to said outer part by said button, said inner part having a head fitting in said first opening; a spring fitting inside said outer part of said stem near said second opening and bearing against the extremity of said head whereby said outer part of said stem eifects an axial movement against said spring independently of said inner part during screwing of said button on said case.

2. Assembly according to claim 1, wherein said spring has a base terminating in a pair of legs disposed parallel to the axis of rotation of the stem, said legs being adapted to grip said outer part of said stern so as to exert a radial pressure thereon.

3. Assembly according to claim l1, wherein said first slot is narrower than said extremity of said head whereby the walls of said slot form a stop limiting the movement of said outer part of said stern thereby preventing overtensioning of said spring.

No references cited.

RICHARD B. WILKINSON, Primary Examiner.

M. LORCH, Assistant Examiner. 

1. A JOINTED WINDING STEM ASSEMBLY HAVING A BUTTON ADAPTED TO BE SCREWED ON A TIMEPIECE CASE, SAID STEM COMPRISING A OUTER PART SECURED TO SAID BUTTON, SAID OUTER PART HAVING FIRST AND SECOND SPACED DIAMETRICAL OPENINGS, SAID OPENINGS BEING CONNECTED BY A DIAMETRICAL SLOT TO FORM A HOUSING; SAID FIRST OPENING BEING DIRECTED TOWARDS THE INSIDE OF SAID CASE AND TERMINATING IN A PAIR OF ELASTIC JAWS DELIMITING A SECOND DIAMETRICAL SLOT, SAID SECOND OPENING BEING DIRECTED TOWARD THE OUTSIDE OF SAID CASE AND TERMINATING IN A THIRD DIAMETRICAL SLOT; SAID STEM INCLUDING ALSO AN INNER PART ROTATABLY AND AXIALLY DRIVEN BY MOVEMENTS IMPARTED TO SAID OUTER PART BY SAID BUTTON, SAID INNER PART HAVING A HEAD FITTING IN SAID FIRST OPENING; A SPRING FITTING INSIDE SAID OUTER PART OF SAID STEM NEAR SAID SECOND OPENING AND BEARING AGAINST THE EXTREMITY OF SAID HEAD WHEREBY SAID OUTER PART OF SAID STEM EFFECTS AN AXIAL MOVEMENT AGAINST SAID SPRING INDEPENDENTLY OF SAID INNER PART DURING SCREWING OF SAID BUTTON ON SAID CASE. 